Sustained molecular remission in a patient with CML in blastic crisis receiving dose-reduced hematopoietic stem-cell transplantation followed by early withdrawal of cyclosporine and prophylactic use of interferon-α

A 54-year-old man with chronic myelocytic leukemia in blastic phase received reduced-intensity transplantation (RIST) from an HLA-identical unrelated donor. The preparative regimen consisted of busulfan, fludarabine, and anti-thymocyte globulin. Graft-versus-host disease (GVHD) prophylaxis was cyclosporine alone. Because he had a high risk of relapse, we discontinued cyclosporine on day 37, but he did not develop any signs of acute GVHD. To induce GVHD and augment a graft-versus-leukemia effect, we initiated interferon-α therapy on day 80 to a maximum dosage of three million units five times a week. He achieved molecular remission on day 94 followed by the development of extensive chronic GVHD the severity of which paralleled to the dose of interferon-α GVHD gradually subsided after discontinuation of interferon-α and the patient remains in molecular remission 18 months after transplantation. This case suggests that early withdrawal of cyclosporine and the prophylactic use of interferon-α are promising in RIST for high-risk leukemia.